Schools in Hackettstown, N.J., were locked down for more than three hours Monday after a report of a man with a gun in the area.
The lockdown was lifted by 2 p.m. after police determined the threat was "unfounded," according to the district's website.
Area schools went on alert at about 10 a.m., shortly after a man called the Warren County Communications Center and said he was armed with an assault rifle in the woods near a high school, police and school officials said.
Students were kept inside while police canvassed the area and parents were urged not to come to the schools.
Ron DiRienzo, 17, told NBC New York that he and other students were herded into the corners of a classroom while the lights were turned out and blinds pulled down. Some kids had to urinate into bottles because they were locked down for so long, he said.
Throughout the town, residents were worried.
"Everybody was scared," said Galo Yoza.
Local law enforcement gave the all clear at about 2 p.m., according to a notice on the district's online announcement page.
"The nature of the threat is a matter of an ongoing investigation," the message read.
Get the latest from NBC 4 New York anytime, anywhere. Follow us on Twitter, Facebook and Google+. Sign up for email newsletters here. Get breaking news delivered right to your phone -- just text NYBREAKING to 639710. For more info, text HELP. To end, text STOP. Message and data rates may apply.